William Robert Monroe, was 41 when he became the fourth Sheriff of St. Lucie County in 1920. Monroe had been a deputy sheriff for some time, and served as Chief Deputy to Sheriff Bill Jones. Sheriff Monroe had a jurisdiction encompassing much of what we now know as Indian River and Martin counties.
Around 4 a.m. on March 25, 1921, about one mile north of John's Island, deputies seized a cabin cruiser loaded with 200 cases of illegal liquor. Three men were arrested, and Sheriff Monroe was called to join them at the Winter Beach dock. As the Sheriff piloted the boat down the Indian River nearing Fort Pierce, the boat exploded, killing him instantly and injuring two other deputies. The Sheriff was 42 years old, leaving a wife and four young children.